共查询到20条相似文献,搜索用时 31 毫秒
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从增敏的角度,分析了光纤Bragg光栅的传感理论,在此基础上研究了光纤Bragg光栅的温度应力增敏原理。从不同的方面阐述了温度应力增敏技术,并进一步分析了光纤Bragg光栅压力温度传感器的增敏模型,研究了光纤光栅传感器的封装增敏技术。 相似文献
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全光纤热光型可变光衰减器 总被引:10,自引:0,他引:10
根据光纤包层中的倏逝场机制,将具有热光效应的聚合物材料直接覆盖在侧边抛磨光纤上,进行了全光纤热光型可变光衰减器(VOA)的研究.根据理论分析,确定了在侧边抛磨光纤的抛磨区上覆盖材料的折射率与纤芯中光衰减量之间的关系,为选择适当折射率的热光材料提供依据.设计适当的侧边抛磨区,利用先进的轮式侧边抛磨技术,制备了侧边抛磨光纤,以达到最佳可变光衰减效果.采用螺绕电极和优化封装,制作出性能优良的全光纤热光型可变光衰减器.性能测试表明,器件插入损耗小于0.1 dB,衰减范围为0~80 dB,偏振相关损耗小于0.02 dB,背向反射大于70 dB.该方法制作的全光纤热光型可变光衰减器具有可用电驱动调控、可靠性高等优点. 相似文献
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Xuewen Shu Allsop T. Gwandu B. Lin Zhang Bennion I. 《Photonics Technology Letters, IEEE》2001,13(8):818-820
We report an investigation of thermal properties of long-period fiber gratings (LPFGs) of various periods fabricated in the conventional B-Ge codoped fiber. It has been found that the temperature sensitivity of the LPFGs produced in the B-Ge fiber can be significantly enhanced as compared with the standard telecom fiber. A total of 27.5-nm spectral shift was achieved from only 10°C change in temperature for an LPFG with 240-μm period, demonstrating a first ever reported high sensitivity of 2.75 nm/°C. Such an LPFG may lead to high-efficiency and low-cost thermal/electrical tunable loss filters or sensors with extremely high-temperature resolution. The nonlinear thermal response of the supersensitive LPG was also reported and first explained 相似文献
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Recently developed micro- and nano-structured optical fiber sensors, with particular reference to surface plasmon resonance (SPR) fiber sensors and photonic crystal fiber (PCF) sensors are reviewed. SPR fiber sensors can have diverse structures such as D-shape, cladding-off, fiber tip or tapered fiber structures. Some of the recently developed novel structures include the use of various types of fiber gratings in SPR fiber sensors. PCF sensors cover diverse recent developments on photonic-bandgap fiber, holey fiber, hole-assisted fiber and Bragg fiber sensors. Major applications of these include gas sensors and bio-sensors. These micro- and nano-structured fiber sensors have attracted considerable research and development interest, because of their distinct advantages, which include high sensitivity, small sensor head footprint and the flexibility of the optical fibers. They are also of academic interest, and many novel ideas are continuously developed. 相似文献
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长周期光纤光栅(LPFG)具有与短周期光纤光栅所不同的光谱特性。它无背向反射光谱,不对光源的稳定性产生影响。基于纤芯基模与包层模的谐振耦合原理和热光效应,LPFG温度传感器利用谐振波长的漂移变化实现对温度的测量,具有很高的灵敏度。介绍了LPFG的制作方法、LPFG温度传感器的工作原理及最新研究进展。由于具有插入损耗小、可用于遥测、精度高和抗电磁干扰能力强等优点,LPFG温度传感器将有广阔的应用前景。 相似文献
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We demonstrate the measurement of the phase shift in a polymethylmethacrylate single-mode optical fiber interferometer, operating at a wavelength of 632.8 nm, up to 15.8% nominal strain in the fiber. The phase-displacement sensitivity is measured to be 1.39 x10 radldrm-1 for this strain range. This strain range is well beyond the yield strain of the polymer fiber and that previously measured for polymer Bragg gratings and silica optical fiber sensors. 相似文献
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光纤布拉格光栅压力增敏的实验研究 总被引:8,自引:4,他引:8
近年来光纤光栅作为压力、温度、应变等传感器已经成功地应用于光纤传感领域中。然而裸露的光纤光栅对于外界物理参量的变化灵敏度不高,因此有必要对光纤光栅进行增敏封装,以提高其对外界环境变化的灵敏度。采用两种聚合物材料均匀混合,将其对布拉格光纤光栅进行封装。在23℃情况下对封装后的光栅进行了压力实验,实验表明用两种聚合物封装后的光栅对压力有很高的灵敏性,在0~10MPa范围内压力灵敏度为-122×10-4MPa,是裸光栅压力灵敏度的62倍 相似文献
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提出在含涂覆层的标准通信光纤中用800nm红外飞秒激光直接写入了长周期光纤光栅(LPFGs)。从理论上分析了光纤涂覆层对于纤芯基模和包层模有效折射率的影响,并进一步研究涂覆层对LPFGs温度灵敏度的影响。分别对制作的去除涂覆层和含涂覆层LPFGs的低阶包层模进行了温度特性实验。结果表明:涂覆层的存在不仅能成为LPFGs理想的保护层,更重要的是将LPFGs的温度灵敏度提高到0.1173 ,与理论分析吻合。这种含涂覆层光纤光栅若作为温度传感器,将有着良好的机械强度和温度灵敏度。 相似文献
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Vazquez C. Montalvo J. Montero D. S. Pena J. M. S. 《Photonics Technology Letters, IEEE》2006,18(22):2374-2376
An improved ring resonator self-referencing technique in a new reflection configuration for remote fiber-optic intensity sensors is demonstrated using fiber Bragg gratings. Sensor sensitivity doubles and a single fiber lead is used. The sensor is interrogated at two subcarrier frequencies having a high rejection of interference from laser source intensity fluctuations and loss in the fiber lead. We experimentally demonstrate the efficiency of the new reflection configuration, the usefulness of the theoretical model proposed, and discuss design parameters for optimum insertion losses 相似文献
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Fiber grating sensors 总被引:21,自引:0,他引:21
Kersey A.D. Davis M.A. Patrick H.J. LeBlanc M. Koo K.P. Askins C.G. Putnam M.A. Friebele E.J. 《Lightwave Technology, Journal of》1997,15(8):1442-1463
We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors 相似文献
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采用相位掩模法,利用紫外光在载氢普通掺锗单模石英光纤中制作出光纤布拉格光栅(FBG)。同时,将反射率为17dB的光栅FBG1和反射率为41dB的光栅FBG2置于30~1000℃的高温炉内进行温度特性比较实验。在30~870℃范围内FBG1和FBG2两者中心波长随温度的变化趋势一致,且两个光栅反射波长都在870℃时消失,当温度继续升高到900℃时,仅有FBG2再次出现反射率为1dB的反射峰。对经过高温处理后的FBG2再次进行30~1000℃温度测量实验,温度灵敏度为0.02nm/℃,线性度为0.999。实验结果表明,对于具有高反射率的FBG进行高温热处理后,其可以在30~1000℃的温度范围内进行传感测量,且中心波长随温度变化呈良好的线性关系。利用该方法可以制作出低成本的可用于高温环境测量的FBG温度传感器。 相似文献
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We describe an active form of a frequency division matrix array network developed to support both interferometric sensors and fiber Bragg gratings to demodulate both quasistatic and periodic measurands. Novel telemetry allows an improved measurement range using a single source and uses a fundamental interferometric principle for self-calibration. High resolution is achieved through active but remote demodulation of passive sensors. A resolution of 0.019 nm with a measurement range of 62.8 μm for an interferometric sensor and a strain resolution of 0.19 με with a measurement range of 6.28 mε was obtained for fiber Bragg grating sensors 相似文献
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Buric M. Tong Chen Maklad M. Swinehart P.R. Chen K.P. 《Photonics Technology Letters, IEEE》2009,21(21):1594-1596
A palladium-coated fiber Bragg grating (FBG) inscribed in high attenuation fiber (HAF) capable of measuring hydrogen concentration at -150 degC, well below the 4% explosion limit, is presented. The low-temperature performance of the sensor was improved by heating the gratings as much as 300 K above the ambient temperature with highly attenuated infrared laser light. The sensitivity and response time of the FBG hydrogen sensor were studied as functions of fiber temperature. Through the selection of length and the loss per meter of the HAF, the self-heating scheme demonstrated here enables numerous FBG hydrogen sensors to be multiplexed in a single fiber for multipoint hydrogen sensing using a single fiber feedthrough. 相似文献